miller



No. 47,118. l PATBNTED APR. 4, 1865. J. A. MILLER.

BOILER PURNACE.

UNITED STATES. PATENT OFFICE.

JOSEPH A. MILLER, OF NEWY YORK, N.- Y.

BOlLER-FURNACE.

Specification thinning part of Letters Patent No. 47, HI8` daten April 4, 1865.

To all whom it may concern;

Be it known that I, Josnrn AQ MILLEIQ,

of No. 200 Broadway, in the city, county, and State of New York, have invented certain new and useful Improvements in Furnaces; and I do hereby declare that the fottowin'g is a full, clear, and exact description ot' the same, reference being had to the accompanying draw ings, forming a part of this specification, in which- Figure l is afi-ont view of a steainboiler Vfurnace constructed according to my invention. -Fion 2 is a central lon itudinal vertical section of the saine. Fig. 3 is a transverse section of the same in the plane indicated-by the liuc :r a: in Fig. 2. Fig. 4 is a horizontal section of the saine in the plane indicated by the line ly y in Figs. 1, 2, and 3. Fig. 5 is ahorizontal section ot part of the door frame and o fthe lowerhiilgeof the firedoor.

Similarr letters of .reference indicate corrcspending parts in the several figures.

One part of my invention consists in a novel system of air ducts, passages,and slits or orifiees at the sides of a steam-boiler or other furnace for the admission of air fromhe ash-Y pit to the tire-chamber above the fucl -to supply the hot gases rising from the fuel with the necessary oxygen to effect their perfect combastion.

the furnace, and thereby obtaining a more perfect mixture of 'the hot gases rising from the fuel with the air admitted through the aforesaid slits or orifices.

Another part of my invention relates to the employment ofua hollow box nre-door, having its inner screen of rebrick or oth er material perforated for the admission to the re of air received through avalve or opening in the frontof the door; and this part of my invention consists in suoli an oblique larrangement of the said perforations in the inner screen that the radiant heat from the fire is prevented from vstriking' directly through the said perforations upon the outer portion of the door, which is thereby kept comparatively cool.

My invention consists, tinally, in furnishing;r the h'ie door with a hollow hinge, through which, when the door is open, there is a cour munication from` a blower or other means of obtaining a current ot' fair t.oopenin gs so pro- Videdin the door or tire-front or" the furnace, or in both, for discharginga sheet or 'sheets ot' cool air across the doorway, and thereby protccting the tireinan from the heat of the tire. To enable others' skilled in the art to construct and apply my invention, I will proceed to describe with reference to the drawings.

A is the fire-chamber of the furnace. B is the grate, and Ois the ash pit. On each side of the ashpit, at the front part thereof, there is the Iopening of a duct, D, which lleads upward to a. horizontal passage, E, extending along the interior of the side wall of the rechamber, at some distance above the grate, and.- connnunicating' with the lirechamber through vertical slits .a a in the bricks ofthe said wall.` The air admitted to the furnace ally passes through the grate and fuel in the usual manner, while a portion passes through the ducts D and passages E, and is admitted above the fuel in jets through the slits aio, and thereby' mixed with the hot gases rising from the fuel in such manner as to brin ginto intimate and thorough admixture with the said gases the necessary oxygen to produce their perfect combustion. The said slitsa a resemble louver-openings, havin'gan in'war I horizontal inclination or Obliquity toward the tire-bridge F and rear ofl the tire-chamber, as shown in Fig. 4,'to give a freer entrance for the gases, which is thereby encouraged by the draft., Dampers or valvesF! areprovided in the ducts D to regulate the admission of The bridge F is. made witl1"a central pier,l

G, which extends up to the bottom of the boiler J or top of .the fire-chamber, so that the openings c c, Fig. 3, for the passage of ,Y the ame and heated` gaseous products of' combustion over the said Wall are at the sides of the furnace and the gases rising from the fuel and seeking an outlet from the fire-chamber are turned toward the side walls, and thereb brought into more intimate admixture with the air entering through the slits a a.

H I is the fire-door, which is of box form or hollow, the front H being of iron and the back or inner screen of tire-brick. There is provided in the front II an opening, d, and a valve, e, for regulating the admission ofair through the said opening to be supplied to the tire'ehamber above the fuel through perforations g gin the back or inner screen, l. These pert'orations are'not parallel with the length of the furnace,but have a'latcral obliquity,as shown in Fig. 4, so that while they allow a. free passage of air to the tire-chamber they prevent the radiant heat-ot' the tire i'rom pass' ing directly through them and striking the front H. In this way not only is the loss of heat by radiation from the door prevented, but the front of the door and its valve c are kept so cool that they can be handled without in zonvenience. The pintle h of the lower hinge of the tire-door and the stationary socket i, which is Vattached to the tire-front K or do r-i'raine, are both made hollow, and the said socket z' has connected with it a pipe,j, from a blowing apparatus. The hollow pintle h communicates with an airduct, I, Figli, within-t' e angle of the door next the hinge, and in the side ot' the door next the liingethereis a vertical slit, m, for the exit ot air from tie duct l. The socket t' communicates with a vertical passage, n, in the lire-front at the side ofthe doorway. The pintle h and socket i are made with openings substantially like those of a cock, so arranged that when the door is shut the said openings are closed, but that when the door is open the said passages are open also, and the air admitted through the pipe j to the socket i is discharged from the slit m and passage n, in thin sheets right across the open doorway, thus forming a screen ot' cold airbetween-the fire and the tireman and protecting the tiremen from theheat of the tire.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. The slits or openings 'a min combination with the horizontal passages E in the side walls ot' the tire chamber, and with the ducts D in communication with the ash-pit, substantiallyas and for the purpose herein speci tied.

2. Giving the openings a. ct an inward hori zontai inclination toward the bridge-wall or rear ofthe tire-chamber, substantially as and forft-he purpose herein specified.

3. 'lhe pier G and side openings, 0 c, bridge, in combination with a system of slits or openings, a a, for the admission of air through the side walls ot' the tire-chamber, substantially as and for the purpose herein specified. ,v

4. The-laterally-oblique arrangemeutot'the pert'orations g g in the back or inner screen, l, of the lire-door, substantially as and for the purpose herein specitied.

5. The hollow hinge h i, in combination with one or more openings, m u, in the door or tire-front, and with a pipe, j, for the introduction ot' air from a blowing apparat-us, whereby a current or currents of cold air are discharged in thin sheets across the open doorway, suhstantially as and for the purpose herein specified.

JOSE PH A. MILLER.

"Witnesses: J. W. Coil/ms, Gr. W. REED.

over th e" 

